SDRP - Did You Know?

The San Dieguito River Park
18372 Sycamore Creek Rd.
Escondido, CA 92025
Phone: (858) 674-2270
Fax: (858) 674-2280

The River Park has converted from a print-based distribution system to a web-based system. If you are interested in receiving e-mail notices when the quarterly activity schedule is posted to the website, and news of special events occurring in the Park, click above to send us an e-mail.

DID YOU KNOW?
by Shawna Anderson

COAST LIVE OAK

Not very many people can claim that the view from their office is of a coast live oak (Quercus agrifolia)! This stately oak covers the entire front window of my office and we are lucky at the River Park office headquarters to have them. Coast live oaks are present throughout much of the River Park particularly around Lake Hodges and San Pasqual Valley. Coast live oaks are one of 18 diverse oak species in California. The genus Quercus comes from the Celtic words quer, meaning fine and cuez, meaning tree. This fine tree was known as "encina" in Spanish, the basis for many place names in southern California including the city of Encinitas. Historically, oak acorns have been an important staple for native Californians and the trees revered for their symbols of fertility, strength, and oneness with the earth. In their natural setting, these majestic trees occur mainly in native plant communities of southern oak woodland, riparian, and coastal sage scrub. They prefer moist sites with deep soil, particularly canyon bottoms and north-facing slopes. Impressive in their stature, they average 20 to 40 feet in height but may grow up to 80 feet high with wide spreading branches of up to 70 feet (although the largest living coast live oak, found near Gilroy, has a crown spread of 127 feet!). Old, gnarled oaks commonly exceed 250 years in age representing the tree's strength and resistance to natural factors such as fires. An oak tree's thick bark protects it from wildfires and can actually slow down the spread of fire.

Not only are oaks beautiful to look at, oak woodlands support hundreds of native bird and animal species providing food, shelter, and nesting habitat. Unfortunately, many of the coast live oaks around Lake Hodges are dying. Alarming to see, many of these large trees stand brown or rapidly deteriorating. Thanks to concerned citizens in the community of Del Dios, some progress has been made to determine the cause of these deaths. Recently, a forest pathologist from UC Berkeley took several samples from the oak trees and determined that a type of pathogen is causing the deaths, especially those trees that are already stressed (from drought or disease). Fortunately, the pathogen is not the Sudden Oak Death pathogen that is rapidly killing acres of oaks in northern California. Work is continuing to determine more about the pathogen and what we should be doing about it.

In the past two decades, urbanization has become the leading cause of oak woodland habitat loss. Although it is important to preserve oaks in their natural setting, coast live oaks can easily be incorporated into native habitat landscape plans in more urbanized areas. Native landscaping can provide a biologically sensitive and aesthetic transition in the urban/wildland interface. Information on backyard native habitats that can be incorporated into your garden is available on the National Wildlife Federation website at www.nwf.org and at the Las Pilitas Nursery in Escondido. Then someday you might also claim a wonderful view out your window of the majestic coast live oak.